review - cooking with rice husk-ethos 2011
DESCRIPTION
By Marc Pare.Marc is working with Enerteam in Vietnam on rice husk gasifier for both domestic and medium scale.TRANSCRIPT
Cooking with Rice Hulls: A Primer on Current Technology,
Projects, and Challenges
Marc Pare, 2011
What about usability?
Rice Hull as Fuel
Low energy density
High ash content (20% volume left over)<5% for wood
Small particle size
Lò Trấu(direct combustion)
Belonio Gasifier(gasification)
Lò Trấu: Breakdown● Available since at least the 1950s ● Common around Vietnam● Features:
● Hands off operation● Continuous● Inexpensive
Drawbacks● Still smokey, even with chimney (unless you
tend constantly)● Start up is slow● Pot size choices limited
Portable Variation● Mayon Turbo, Quasi-gasifier, …● Same principle of direct combustion
Requires constant, skilled tending
Belonio Gasifier
Belonio Gasifier: Breakdown● By Dr. Alexis Belonio in the Phillipines● TLUD with Fan● Blue flame (sexy)● Emissions like a gas stove● Great thermal performance● Lights up almost instantly● Nice turn-down with fan● Wonderful handbook. “Rice husk gas stove
handbook”
Brother Kent Good in Cambodiahttp://web.mac.com/kentcgood/
Belonio Gasifier: Drawbacks
● Loading and unloading is inconvenient● Wind puts flame out easily● Disastrous failure mode if left on
● RESULT: 10% adoption rate (Vietnam National University, 200 stove study)
Remote Burner● One possible solution: downdraft operation,
burn gas in separate burner● Allows continuous operation
Remote Burner● BUT
● Lighting now not as easy● Persnickety burners● Tar collection in pipes
(cooking gasifiers are run largely in the pyrolysis mode, not gasification. 90 SGR* vs. 140 SGR for gasification)
*SGR: Specific Gasification Rate [kg / hr-m^2]
Rice husk cook stoves: Many designs are technically possible, but no product exists that balances technical feasibility with user needs at a large scale.